Via elasticsearch 2.1 we have written a custom Lucene TokenFilter that adds
a payload to a special term during indexing analysis, and we also have
custom Lucene Query/Weight/Scorer classes that compare this payload against
some query data to decide if a document matches a query or not.
I know that the payloads are being written as desired since I can easily
see them via elasticsearch's termvector API.
However, while our Scorer can see all of the documents with this special
term, I can never get access to its payload.
The approach to doing this in the Scorer is simply:
docs = leafReaderContext.reader().postings(specialTerm, PostingsEnum.PAYLOADS);
Then, walking through the docs via nextDoc() and trying to retrieve each
doc's payload via:
BytesRef payloadRef = docs.getPayload();
if (payloadRef != null) {
byte[] payload = payloadRef.bytes;
}
I have logging in place so that I see that every document I have in a test
index is being looked at, but for every document, the payloadRef comes back
null.
What am I doing wrong? Is there some setting I need to enable somewhere to
allow the postings method to do what it says it can do?
Is there a better way to do this?
Any advice would be appreciated!
Bob
